Locking Device

Abstract

The invention relates to a locking device to radially lock a rotatable cylindrical element, where the locking device ( 1 ) comprises a roller element ( 2 ) and at least a first inclined surface ( 3 ). The locking device is arranged to be positioned in relation to a cylindrical surface ( 13 ) around the cylindrical element ( 12 ) in such a way that the distance between a starting point ( 10 ) of the first inclined surface ( 3 ) and the cylindrical surface ( 13 ) is larger than the diameter of the roller element ( 2 ) and that the distance between an end point ( 11 ) of the first inclined surface ( 3 ) and the cylindrical surface ( 13 ) is smaller than the diameter of the roller element ( 2 ). The locking device further comprises means ( 6 ) to selectively enable the roller element ( 2 ) to be distanced from the cylindrical surface ( 13 ). The advantage of the invention is that a locking device can be obtained in an easy and cost-effective way.

1 . A locking device to rotationally lock a rotatable cylindrical element, the locking device comprising:
 a roller element having a diameter, and   a body having an inclined surface with a starting point and end point, the locking device being positionable in relation to a cylindrical surface extending about the cylindrical element such that a distance between the starting point of the inclined surface and the cylindrical surface is greater than the diameter of the roller element and a distance between the end point of the inclined surface and the cylindrical surface is lesser than the diameter of the roller element such that the roller element is releasably engageable with the inclined surface and with the cylindrical surface to prevent rotation of the cylindrical element,   means to selectively position the roller element with respect to the cylindrical surface.   
     
     
         2 . The locking device according to  claim 1 , wherein the locking device has a radial centreline, the inclined surface is a first inclined surface, and the locking device further comprises a second inclined surface with a starting point and an end point, the second inclined surface being positioned opposite from the first inclined surface relative to the radial centreline and positioned in relation to the cylindrical surface such that a distance between the starting point of the second inclined surface and the cylindrical surface is greater than the diameter of the roller element and a distance between the end point of the second inclined surface and the cylindrical surface is lesser than the diameter of the roller element. 
     
     
         3 . The locking device according to  claim 2 , wherein the first and second inclined surfaces are symmetrical about the radial centreline. 
     
     
         4 . The locking device according to  claim 1 , wherein the means to selectively position the roller element with respect to the cylindrical surface is a lifting device, the lifting device being activateable to lift the roller element from the cylindrical surface in order to place the locking device in a released state. 
     
     
         5 . The locking device according to  claim 4 , wherein the lifting device is a magnet. 
     
     
         6 . The locking device according to  claim 5 , wherein the lifting device is an electromagnet. 
     
     
         7 . The locking device according to  claim 4 , wherein the locking device further comprises a spring element configured to bias the roller element towards the cylindrical surface when the lifting device is disengaged. 
     
     
         8 . The locking device according to  claim 1 , wherein the locking device further comprises means to detect when the roller element is in a lifted state. 
     
     
         9 . The locking device according to  claim 1 , wherein the locking device further comprises means to detect if the locking device is arranged in one of a first locked state and second locked state. 
     
     
         10 . The locking device according to  claim 1 , wherein the roller element is a ball. 
     
     
         11 . The locking device according to  claim 1 , wherein the roller element is a cylinder. 
     
     
         12 . The locking device according to  claim 1 , wherein the cylindrical surface is a surface of the cylindrical element. 
     
     
         13 . The locking device according to  claim 1 , wherein the cylindrical surface is a surface of a tubular element coupled to the cylindrical element by means of a friction coupling. 
     
     
         14 . The locking device according to  claim 1 , further comprising a hinge pin, the locking device body being pivotable upon the hinge pin. 
     
     
         15 . The locking device according to any  claim 1 , wherein the locking device further comprises a second roller element, second means to selectively enable the second roller element to be distanced from the cylindrical surface, and an additional inclined surface. 
     
     
         16 . The locking device according to  claim 15 , characterized in that the locking device further comprises at least a second additional inclined surface, the second additional inclined surface being positioned opposite from the first additional inclined surface relative to a radial centreline of the locking device. 
     
     
         17 . (canceled)